The present disclosure relates to systems, methods, and devices for thought-controlled neuromuscular stimulation. Generally, the system may be used to receive thought signals indicative of an intended action and provide electrical stimulation to a damaged or degenerated neuromuscular region to effectuate the intended action. Methods to produce a flexible neuromuscular stimulation cuff are also disclosed. The device may be a neuromuscular stimulation cuff which delivers stimulation to restore movement to parts of the body not under volitional control due to damaged or degenerated neural pathways from spinal cord injury, stroke, nerve damage, motor neural disease, and other conditions or injuries. The system can also be used in a patient that has some local neural or muscle degeneration for therapeutic or rehabilitation purposes.
Subcutaneous implantable neurostimulation cuffs have been commonly used to block pain and to restore function to damaged or degenerative neural pathways. These implantable cuffs are wrapped around a target nerve and generally include one or more electrodes arranged to stimulate the nerve. By including more than one electrode and/or a different geometry of electrodes, implantable cuffs such as the flat interface nerve electrode (FINE) have been able to achieve stimulation selectivity at the level of individual nerve vesicles.
Transcutaneous neurostimulation cuffs behave similarly to implantable cuffs, however there are important differences. Because the electrodes are placed against the skin, rather than through it, stimulation is preferably performed on skeletal muscle tissue or muscle groups, rather than peripheral nerves located deeper under the skin. Muscular stimulation may be preferable to stimulating major peripheral nerves, e.g. ulnar, median, radial nerves, as stimulating these nerves may cause a patient to feel a tingling sensation. By increasing the number and layout of electrodes in a neuromuscular cuff, similar to the direction taken with implanted nerve cuff designs, current generation neuromuscular stimulation cuffs have been able to selectively stimulate individual muscles or muscle groups.
Flexible transcutaneous cuffs have been developed which fit around a human appendage such as a forearm to control the wrist or fingers. These flexible cuffs may include sensors which record muscle activity, or EMG signals, and stimulate in response to the EMG signals. Thin film technologies have also become important in the development of functional electrostimulation (FES) devices. Devices incorporating thin film technology are often based on a polyimide substrate covered by a chromium, gold, or platinum film.
Current neuromuscular cuffs present many limitations, for example, their inability to receive a stimulation signal which is directly processed from thought signals. These neuromuscular cuffs are also not flexibly positioned over multiple stimulation points. Flexible electrode positioning is desirable when attempting to restore complex muscular movements through neuromuscular stimulation. Current neuromuscular cuffs are also incapable of accommodating a wide range of patient appendage geometries, e.g. varying circumferences, while also staying well adhered to the skin.
An effective wireless system for transmitting human brain signals directly to muscles, and thereby enabling movement through thought-control, has not yet been developed. Neuromuscular stimulation cuffs for such a system, e.g. which receive an input consisting of encoded “thought” signals and provide stimulation to muscular regions according to the signals, have also not been developed.